Which Mimecast End User App can Continuity Mode not be enforced upon by the Administrator?

The Mimecast Personal Portal is the correct answer because Continuity Mode is designed primarily for applications that facilitate email access directly on devices or applications that interface with email services. The Personal Portal is a web-based interface that allows users to manage their email but does not operate in the same context as the other applications. Continuity Mode is more suited for mobile and desktop applications like Mimecast Mobile, Mimecast for Outlook, and Mimecast for Mac, which are intended to provide direct email access and services during email server downtime.

The Personal Portal serves as a web-based alternative for accessing emails and managing settings from any web browser, which inherently limits the ability to enforce Continuity Mode. This mode relies on the infrastructure of dedicated applications to facilitate resilience and seamless operation, while the Personal Portal focuses on user access rather than acting as a direct client application.